Yes the boost comes on quiet slow. The tuner did say the motor feels a little lazy, ie low compression. I remember the engine builder saying it was around 8.4 which I was happy with at the time.dirtygalant wrote:yeah that boost build up curve is not the best.. it almost looks like it's building up and as soon as it builds decent boost the wastegate keeps it steady at 21psi, I would try raising that up to 25psi and see how much power you get - my thoughts are that the turbo is perhaps a bit too big for your relatively low boost and mid-range power orientated application.
Other things I would be looking at is perhaps ignition timing, camshaft timing and that the camshaft duration is ideal for your application. Out of curiousity, have you done a compression test on the engine recently? if so what are the numbers?
The boost is steady once is gets to full boost but the tuner did say that the motor behaves like its got a restricter in the system like the rally cars use. The power builds up then drops off before red line.
I did mention to the tuner about 25 psi which he would be happy to wind into the motor. But the fact it looses power before red line does worry me a little and Id like to get that sorted before I wind more psi into it.
The tuner did check the ignition timing and camshaft timing. Ive got standard VR4 cams but the tuner didnt seem to think that they would be slowing things down much.
Ill also be checking for a pressure drop on either side of the intercooler.
